Saturday, November 16, 2013

Steam Gauges Installed

The first work day after the certification. It felt great! Now I am working for myself and not for the certification and no more ELSA restrictions.
So, I decided to install the steam gauges at this point as I'd like to have a backup for my Dynon system.

They fit nicely. Only the altimeter needed a bit of the paint removed from the edge of the cutouts.



Then I worked on setting up the pitot pressure test. I used a PVC hose attached to the pitot tube and long enough to be able to blow into it while watching the ASI.



I used a piece of 5/16" tubing as a sleeve to connect the pitot hose to the ASI.



Although the pitot tube is not secured inside the PVC tube, this setup gave me great leak test results. From 120kts down to 110 in 4 minutes and 17 seconds, the whole test took 24 minutes (down to 80 kts). I ran the Dynon in parallel once I had established the pressure and the gauge is within a few knots of the Dynon.
I might add two cable ties on the pitot tube side tomorrow just for good measure and longevity.

Unfortunately, I had forgotten to bring a few pieces of PE tubing to hook up the static ports of the ASI and the altimeter to the static Y-connector.
So I decided to attach the tail fairing instead. I reinspected the area closely before closing it up - for the first time.



The fit is tight and we will see if I get some chafing in flight. The thing that surprised me is that the trim assembly is not well centered within the fairing.


It really is the assembly as the rudder measurements in the PAP use the trim assembly as a reference point and my numbers show the offset is clearly to the right of the centerline of the aircraft. However, there is no bending or friction or anything, so I leave it as is for now.

I left airport after this task and brought some homework with me.


This suction cup is from a removable hanger and fits over the static port and stays clear of surrounding rivets. I drilled an undersize hole in the base and inserted a 1/4" PVC tube and sealed it in with the Dynaflex silicone. Once cured the silicone will be clear and it should seal well enough for a low vacuum test.
I plan on putting this over one static port rivet and once I put a vacuum on the system it should stay on by itself.
We'll see if it works...

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